Setting up a Quantum LTO5 Tape Drive on Debian

Recently at The Station we’ve decided to enter into digital data backup and archiving. What, you may ask, don’t we do this already? Well, typically in the past at the end of an edit job, the client has been happy to take away, for example, a Digital Betcam or HDCAMSR video tape. However, over the last twelve months, more and more clients are shooting digitally (tapeless) and also asking for digital delivery of final master assets. Therefore, we would like to offer as a service long-term data archiving. Spinning disk is not the best platform for this. Drives can fail, and to set up up a totally secure SAN is an expensive proposition.

Enter the world of data tape. The most recent advance, although at least twelve months old now, is LTO5. This format can store up to 1.5TB of uncompressed data, or 3TB of compressed data on one tape. Single tape, desktop drives are in the region of £2,500 and tapes retail around £60 (I’m sure better prices can be found if one tries). LTO data tape is an excellent, cost-effective medium for long-term archival purposes.

One of the great advantages of LTO5 is that drives can be mounted with LTFS and they simply appear as any other attached storage device. Files can be dragged and dropped to and from the tapes. Transfer rates are allegedly in the region of 140Mbps. We have secured a loan Quantum LTO5 drive from the excellent people at Era UK, via an introduction by our friends at JCA. Of course I was intending to connect this drive to a Linux machine, there was never any question about it. Unfortunately, Quantum only officially supports Red Hat and SuSe (I’m guessing Fedora and CentOS would probably work too), for which they provide compiled binaries. Now, I’m a Debian person and the best available machine had Squeeze installed. You know what’s coming next, and I love a challenge.

Start by downloading the source from Quantum. Unfortunately compiling this source wasn’t as simple as configure, make, make install. After installing the dependencies:

Not really knowing how to solve this initially, I decided to see what would happen if I compiled these sources on my little Ubuntu 10.04 NBR netbook. Of course, the sources compiled without error, but a netbook is not really the device I wish to connect an LTO5 drive to. So, it seemed like there was some sort of Debian Squeeze related package error.

I’m not ashamed to say that I posted to LinuxQuestions.org and a user by the name of knudfl came up with the solution. Behold, the power of the Internet. After removing the development files for libicu44, and installing the relevant counterparts from libicu42, following the suggested directions, I was able to finish compiling the driver. Great, here we go…..

Not so fast. The next step is to format a tape. The supplied documentation from Quantum suggests the following:

More investigation finds that /proc/scsi is a legacy way of dealing with scsi devices, and in the Debian kernel this has been disabled. The good news is that, there is an option within menuconfig to turn this on, but it does mean compiling your own kernel. A new challenge for me as I’d never needed to do this before.

More help from the Interwebs, and using a very helpful tutorial page, I was able to build my own custom Linux kernel (2.6.39 if you’re interested). It wasn’t hard at all.

Booting into this kernel and everything seems to work fine. The final problem is:

Related

So – You can generally only go back one previous version of LTO tape, i.e. you can have LTO5 drives reading LTO4 tapes, but LTO3 is generally considered a no-no. I assume you are using TAR to read/write files onto the tape, which is great, but wondered what MAM or catalogue you were using. I think that /proc/scsi has actually been disabled in 2.6.39 anyway [its not just a Debian thing].

You can read back two generations, but you can only write back one generation, which is why you were unable to format the LTO3 tape. However, LTFS can only be stored on LTO-5 cartridges. Congratulations on getting this to work!